Offset proof press



May 23, 1961 E. o. vANDl-:RcooK 2,985,102

OFFSET PROOF PRESS Filed Oct. 13, 1958 4 Sheets-Sheet 2 Edward 0. Vkldercoo/c @W wrrgg May 23, 1961 E. o. vANDERcooK 2,985,102

OFFSET PROOF PRESS 4 Sheets-Sheet 3 Filed Oct. 13, 1958 E. 21:21-' Edward 0. Vandercoo/c @M4 ZZ g5 May 23, 1961 E. o. vANDERcooK 2,985,102

OFFSET PROOF PRESS Filedv Oct. 13, 1958 y4 Sheets-Sheet 4 Inf/E 2&2" du/ara 0. VlmercOa/L OFFSET PROOF PRESS Edward 0. Vander-cook, Kenilworth, Ill., assignorto Vandercook & Sons, Inc., Chicago, Ill., a corporation of Delaware Filed Oct. 13, 1958, Ser. No. 766,870 6 Claims. (Cl. lOl-146) This invention relates to offset proof presses adapted to use a plate which is chemically processed to form moisture-receptive non-printing areas and non-moisturereceptive printing areas corresponding to the image to be reproduced. In such presses, a blanket cylinder and dampening and inking rollers are mounted on a carriage reciprocable over spaced stationary beds which carry the plate and a sheet to be printed, with means being provided to control engagement of the cylinder and rollers with the plate and sheet.

Moisture is first applied over the surface of the plate, by means of the dampening rollers, to be retained in nonprinting areas thereof after which ink is applied by the inking rollers, to be repelled from the moistened areas and retained by the non-moistened printing yareas and thereby form an image on the plate. The image is transferred from the plate to the blanket cylinder and thence from the blanket cylinder to the sheet.

In prior machines of this type, the inking rollers are mounted on the forward end of the carriage and the dampening rollers are mounted on the rearward end of the carriage, the blanket cylinder being mounted -between the inking rollers and the dampening rollers. At the forward end of the machine, ink is applied to the inking rollers and on rearward movement of the carriage, the blanket cylinder and dampening and inking rollers are all tripped to elevated positions so as not to engage the sheet. On reaching the plate bed during rearward movement, the dampening and inking rollers are automatically lowered so as to sequentially contact the plate but the blanket cylinder remains tripped. At the rearward end of the machine, Water is applied to the dampening rollers, and on travel of the carriage in the forward direction, the inking rollers, blanket cylinder and dampening rollers all contact the plate in that order. The impression on the blanket cylinder is transferred to the sheet of paper on the paper bed as the blanket cylinder moves thereover, both the dampening and inking rollers lbeing automatically tripped when they are over the paper bed.

With such prior art types of machines, it has been found necessary to exercise considerable care in the operation of the machine, and particularly in regard to o taining the proper amount of moisture on the plate. With too little moisture, the non-image areas will pick up ink to cause a distortion generally referred to as scum while too much moisture results in greying out of the image. To reduce such distortions, it has been necessary to accurately adjust and cont-rol the application of water to the dampening rolls and the application of water from the dampening rolls to the plate. The type of plate used has also been an important consideration, the best results being obtained with plates having considerable grain or porosity in the non-image areas so as to retain moisture. It has also been found important to accurately control the humidity in the space about the machine and to avoid drafts over the plate. However, with skillful operation, the proper type of plate and properly controlled conditions, very good results have been obtained and the prior 2,985,102 Patented May 23, 1961 machines have been considered to be generally satisfactory.

This invention resides inthe discovery of comparatively simple changes in construction and operation of an offset proof press by which greatly improved results are obtained, particularly with respect to the application and control of moisture and ink on the plate.

According to this invention, a dampening roller engages the plate during movement of the carriage in one direction, immediately followed by the inking rollers, and on movement of the carriage in the reverse direction, the inking rollers are tripped. Thus the inking rollers engage the plate only during movement of the carriage in one direction (instead of engaging during movement in both directions as in prior presses) and twice as many inking rollers are required to obtain the same efliciency in the application of ink. However, this apparent disadvantage is more than offset by a great improvement in moisture control.

In particular, it is found that with the inking rollers engaging the plate only at a time immediately after the dampening rollers, there is substantially no evaporation of moisture from the plate. As a result, it is possible to control the amount of moisture with much greater ease and precision and, in addition, press room changes in humidity have substantially no effect on the inking process. Further, it is possible to use plates of all types and it is even possible to use plates in which the non-image areas have substantially no grain or porosity, it being impossible to use such plates in prior machines except with manual application ofthe moisture to the plate.

Another feature of the invention is in the mounting of the inking rollers on the carriage between the dampening roller and the blanket cylinder, with the dampening roller, the inking rollers and the `blanket cylinder being engaged with the printing plate sequentially on movement of the carriage in one direction. Thus the inking rollers are engaged with the plate only immediately after engagement by the dampening rollers, to obtain the advantages mentioned above, and the blanket cylinder is engaged with the plate immediately after engagement by the inking rollers. With this feature, the ink on the plate is completely fresh at the time it is engaged by the blanket cylinder, and cannot be dried out or affected by changes in humidity conditions.

A further feature of the invention is in the application of ink and water to the inking rollers and dampening roller only at the rear end of the machine. With this feature it is not necessary to stop for any substantial length of time at the forward or front end of the machine, and the total time required to complete a cycle is reduced. Also, the drive of ink and water applying drums is simplified.

This invention contemplates other and more specific objects, features and advantages which will become more fully apparent from the following detailed `description taken in conjunction with the accompanying drawings which illustrate a preferred embodiment and in which:

Figure 1 is a side elevational view of an offset proof press constructed according to the principles of this invention; the rearward portion of the machine being shown in the upper portion of the figure, and the forward portion of the machine being illustrated in the lower portion of the ligure;

Figure 2 is a sectional view taken substantially along line lI-II of Figure 1, showing the construction of cams used to control movement of a dampening roller;

Figure 3 is an enlarged side elevational view of the carriage of the press of Figure 1, with portions of the casing being broken away to show the construction of the mechanisms used to control vertical movement of the blanket cylinder, the inking rollers and the dampening rollers;

Figure 4 is a sectional View taken substantially along line IV-IV of Figure 3, illustrating the mechanism used to` control vertical movement ofthe blanket cylinder;

Figure 5 is a sectional view taken substantially along V-V of Figure 3, illustrating the mechanism used to control vertical movement of an inking roller; and

Figure 6 is a sectional view taken substantially along line VI-VI illustrating mechanism used to control vertical movement of the dampening roller, such mechanism being operated by the cams illustrated in the sectional view of Figure 2.

Reference numeral 1l) generally designates a printing press constructed according to the principles `of this invention. The press '11B comprises a carriage` 11 mounted on an elongated frame 12 for reciprocable movement. As illustrated in the upper portion of Figure l, the carriage 11 is at the left-hand end of the frame 12, hereinafter referred to as the rear or rearward end. The carriage 11 is movable forwardly, to the right as viewed in Figure l, to successively pass a plate bed 13 and a sheet bed 14 supported in spaced relation in the frame 12. After reaching the front or forward end of the machine, the right-hand end as illustrated in the lower portion of Figure l, the carriage is of course moved back to the initial rearward position as illustrated in the upper portion of Figure l. This movement of the carriage is preferably effected through a motor drive arrangement, not illustrated, of a type known in the art, although it could be effected by hand.

Journalled on the carriage 11 are a dampening roller 15, four inking rollers 16, 17, 18 and 19, and a blanket cylinder 2li. In the normal printing operation of the machine, the carriage moves forwardly, to the right as illustrated in Figure 1, and the dampening roller 15 is engaged with a plate on the plate bed 13 to apply moisture thereto. This moisture is retained by moisturereceptive non-image areas of the plate. The plate is then engaged successively by the inking rollers 16-19, the ink being retained on non-moistened image areas of the plate. The plate is then engaged by the blanket cylinder Ztl'having a resilient surface formed by a sheet of rubber or the like, to cause Ytransfer of the image from the plate to the surface of the cylinder.

Upon reaching the sheet bed, the dampening roller 15 and the inking rollers 16-19 are tripped upwardly so as not to engage a'sheet on the bed 141.` The blanket cylinder, however, engages a sheet on the bed 14 to transfer the image thereto.

AfterV reaching the right-hand front or forward end of the machine, the carriage is moved back toward the initial rear position as illustrated. During this movement, the blanket cylinder 2t) and the inking rollers 16-19 are tripped upwardly so as notV to engage either the sheet on the bed 14 or the plate on the bed 13. The dampening roller 15, however, may be lowered to engage the plate on the bed 13, to maintain moisture in the moisture-receptive areas of the plate.

It is to be noted that as the blanket cylinder passes over the plate, moisture is picked up leaving the plate almost dry, and complete drying of the plate will result in damage thereto to prevent satisfactory operation. With the machine of this invention, the carriage is immediately moved rearwardly after reaching the forward position and moisture is applied to the plate to thus prevent complete drying thereof.

It may also be noted that-the amount of moisture applied to the plate, at the time the inking rollers are engaged therewith, is determined primarily by the amount applied during forward movement of the machine and there can be substantial variations in the amount applied during rearward movement as well as in the amount of evaporation between the rearward and forward movements, without adversely affecting the inking process. It is, however, very important that the plate be dampened on the rearward movement, to prevent complete drying thereof and damage thereto as pointed out above.

When the carriage is returned to the initial rearward position as illustrated, water is applied to the dampening roller 1S and ink is applied to the inking rollers 16-19, in preparation for the next cycle of operation. This simultaneous application of water and ink greatly reduces the time required for acomplete cycle of operation. The time required for a complete'cycle is further reduced in that a printed sheet may beremoved `from the sheet bed 14, and a new sheet may be installed, during the simultaneous application of water and ink.

To apply water to the dampening roller, a cylinder 21 is journalled in the frame 12` as diagrammatically illustrated in dotted lines in Figure l, to engagel the underside of the dampening roller15 in the rearward position of the carriage 11 as illustrated. Another cylinder 22 is engaged with the cylinder 21, to control the amount of water on the periphery thereof, and a receptacle 23 is mounted below the cylinders 21 and 22. A distributor roll 24 is mounted on the carriage to engage the upper side of the dampening roller 15. Preferably, the dampening roller 15 lhas a resilient surface of rubber or the like, while the distributor roller 24 has a hard surface of steel or the like.

To apply ink to the inking rollers 16-19, a pair of drums 25 and 26 are journalled in the frame 12, to respectively engage the underside of the inking rollers 17 and 19. Vibrator rolls 217, 28, and 29 are mounted on Vthe carriage to respectively engage between upper side portions of rollers 16 and 17, between upper surface portions of rollers 17 andA 18, and between `upper surface portions of rollers 18 and 19. The vibrator rolls 27-29 are preferably arranged to be axially reciprocated as they are rotated, to obtain uniform distribution of ink over the surfaces of the inking rollers.

The positioning of both the water-application means and the ink-application means at one end of the machine facilitates drive thereof from a common source. As diagrammatically illustrated in Figure l, this drive may cornprise an electric motor 30 coupled to a gear-reduction unit 31 to drive a sprocket 32. A chain 33 extends rearwardly and upwardly from the lower side of sprocket 32 over a sprocket 34 atiixed to the drum 26, thence forwardly over a sprocket 35 connected to the drum 25, thence downwardly and forwardlyabove the underside of an idler sprocket 3,6, thence forwardly and upwardly above a sprocket 37 afxed to the cylinder 21, and thence rearwardly and downwardly to the lower side of the drive sprocket 32.

Referring to Figures 3 and 4, the blanket cylinder 2Q is journalled on `a shaft 3S carried on an arm 39 journalled in the casing, the axis of the shaft 38 being displaced or eccentric to the axis of rotation of the arm 39. The arm 39 is connected through a link 40 to a crank arm 41 which is aixed to -a gear 42- rotatable on a shaft 43 ati'ixed to the carriage. The gear 42 meshes with a sector gear 114 keyed to a shaft 4S which is journalled by the carriage, the inner end of `the shaft d5 being secured to an arm 46 which carries a roller 47. The roller 47 projects inwardly into a cam track on a side of the main frame, to control the vertical position of theblanket cylinder.

In the operation of the mechanism as thus far described, movement of the roller 47 results in rotation of the sector gear 44 in a counterclockwise direction as viewed in Figure 3, to rotate the gear 42, together with the crank arm 41, in a clockwise direction, to move the link 40 upwardly and rotate the arm 39 in a clockwise direction, to lower the blanket cylinder 20. Accordingly, movement of the roller 47 upwardly causes movement of the blanket cylinder 20 downwardly.

Referring nowto VFigure l, when the carriage is in the rearward position as illustrated, the roller 47 is positioned below the lower surface of a horizontal bar 48 aixed to the side of the frame 12. When the carriage is moved forwardly to a position such that the blanket cylinder is disposed adjacent the left-hand or rearward edge of the plate bed 13, the roller 47 engages the upper surface of a cam 49 to cause the roller 47 to move upwardly and to cause the blanket cylinder to move downwardly to engage a plate on the plate bed 13. With further movement in the forward direction, the roller 47 rides over the upper sur-face of a horizontal bar 50, and thence. over the upper surface of a control cam 51A and thence over the upper Surface of another horizontal bar 52, the roller 47 being thus maintained in an elevated position, to maintain the blanket cylinder in a lowered position for engagement with a sheet on the sheet bed 14.

When the blanket cylinder 20 reaches the forward end of the sheet bed, the roller 47 engages the lower surface of a cam plate 53, to cause the roller 47 to move downwardly and thus raise or trip the blanket cylinder to an elevated position. At this time, the roller engages the upper surface of a control cam 54 to pivot the same downwardly against the action of a spring, not shown, acting thereon. At the completion of the forward movement, the roller 47 is in a downward position, with the blanket cylinder 20 being elevated or tripped, and the control cam 54 is returned to the position as illustrated through the action of the spring means acting thereon.

When the carriage is then moved in the rearward direction, the cam roller 47 moves under the cam 54, under the plate 52, then under another control cam 55 adjacent the cam 51, then under the bar 50, and then engages the lower surface of the control cam 49 to move the same upwardly against the action of a spring, not shown, acting thereon, the roller 47 then moving under the bar 43 to the initial position. Thus on return movement, the blanket cylinder is maintained in a tripped or elevated position, so as not to engage either a sheet or a plate.

The above-described control of the blanket cylinder 20 is that used in a normal printing operation. In certain circumstances, and particularly when initially setting up and adjusting the operation of the machine, it is desirable to prevent engagement of the blanket cylinder 20 with either or both the plate or the sheet, during forward movement, and it is desirable to cause engagement of the blanket cylinder 20 with either or both the plate or the sheet on rearward movement. For this purpose, the control cams 49, 51, 53 and 5S may be manually controlled to secure any of such operations as may be desired.

Referring now to Figures 3 and 5, the inking roller 18 is disposed on a shaft 56 one end of which is journalled by a bearing 58. The bearing 57 is secured to the upper end of a rod 58 journalled for a vertically slidable movement in the carriage. The rod 58 has a downwardly facing shoulder 59 which rests against a cam 6G affixed to a shaft 61 which is journalled by the carriage. The inner end of the shaft 61 is aixed to an arm 62 zwhich carries a roller 63, which operatively engages in cam tracks formed on the side of the frame 12.

In the operation of this mechanism, as thus far described, movement of the roller 63 upwardly results in rotation of the arm 62 and cam 60 in a clockwise direction as Vie-wed in Figure 3, to move the rod 58 upwardly and thus elevate one end of the shaft 56.

A similar mechanism is provided at the other end of the inking roller 18, and similar mechanisms are provided at both ends of each of the inking rollers 16, 17 and 19.

The vibrator roll 28 is supported on a shaft 64, one end of which is `carried by a plate 65 which carries a pin 66 disposed in the slot of a plate 67 on the upper end of an upright member 68 secured to the bearing 57 to be carried -by the push rod 58. A similar support is provided at the other end of the vibrator roll 28, and similar supports are provided at both ends of the vibrator rolls 27 and 29. If desired, means, not shown, may be provided for moving the plate 65 `and similar plates of the other mechanisms upwardly to move the vibrator rolls 27-29 out of engagement with the inking rollers 16-19.

Referring now to Figure l, the roller 63, and similar rollers for controlling the other inking rollers, are initially disposed on a horizontal surface 69 of the side of the frame, below a bar 70, when the carriage is in its rearward position. When the carriage is moved forwardly, the control rollers engage -an upwardly inclined cam surface 71a to elevate the same and cause the inking rollers to clear the rearward edge of the plate bed, which may be raised slightly above the level of the plate. The control rollers then ride on a horizontal surface 7i1b and then a downwardly inclined surface 7\1c to be brought back into engagement with the .surface 69 and to move under a bar 72 affixed to the side of the frame. The inking rollers will then be engaged with a plate on the plate bed 13.

When the inking rollers reach the forward end of the plate bed '13, the control rollers engage an upwardly inclined cam surface 73, to be elevated and to then engage the upper surface of a bar 74 secured to the side of the frame. The inking rollers are thereafter maintained upwardly in the remainder of the forward movement of the carriage, so as not to engage a sheet on the sheet bed 14. During movement up the cam surface 73, the control rollers engage a control cam 75 to pivot the same upwardly out of the path of the control rollers, against the action of spring means, not shown.

On return movement of the carriage in the rearward direction, the control rollers ride over the upper surface of the bar 74, then over the upper surface of the control cam 75, and then over the upper surface of the bar 72. The control rollers then engage a control cam 76, to pivot the same downwardly against the action of spring means, not shown, and to ride over the upper surface thereof. The control rollers then ride down the surface 71a, to return to their initial positions. Accordingly, the inking rollers are tripped upwardly on rearward return movement of the carriage, so as not to engage a plate on the plate bed.

The above-described operation is for normal printing. ln some circumstances, particularly when setting up the machine, it may be desirable to engage the inking rollers with the plate on return or rearward movement of the carriage. 'For this purpose, the control cam 75 may be pivoted upwardly, to direct the control rollers down the inclined surface 73 and under the bar 72.

It should be noted that cam tracks similar to those thus far described are provided on the opposite side of the frame, for control of the opposite ends of the inking rollers.

Referring now to Figures 3 and `6, the dampening roller 15 is mounted on a shaft 77 which is journalled in a bearing 78, supported on the upper end of a rod 79, which is journalled for vertically slidable movement in the carriage. The rod 79 has an inclined lower surface 80 engaged by the upper surface of a'wedge member 81 which at its inner end journals -a roller '82 for rotation about a vertical axis. The wedge member 81 is slidable on a plate 83 secured to the casing and is urged inwardly by a spring 84.

The roller 82 is engaged with cam sur-faces on the side of the frame to cause engagement of the dampening roller 15 with the cylinder 21 in the rearward position of the carriage and to cause engagement of the dampening roller 15 with a plate on the bed '13 in both forward and rearward movement of the carriage.

In particular, when the carriage is in its initial rearward position, the roller 82 engages a surface 85' such that the wedge member 81 is at the limit of its inward movement, and the push rod 79 is at the limit of its downward movement, to thus engage the dampening roller =15 with the cylinder 21.

As the carriage is moved to the right, the roller 82 engages an outwardly inclined surface 86 of a member 7 37 secured to the side of the frame (see Figure 2) to thus cause the wedge member 81 to move outwardly and elevate the dampening roller 15. rIhe dampening roller then clears the rearward edge of the Splate bed 13.

With further movement in the forward direction, the cam roller 82 Vengages an inwardly extending surface 88 of the member l57, to allow the wedge 81 to be moved outwardly under the forces exerted `by push rod 79 and spring 84, to thus lower-the dampening roller into engagement with a plate on the plate bed.

With further movement in the forward direction, and as the dampening roller reaches the forward end of the plate bed, the roller 82'engages an angularly outwardly extending surface 89 of a bar 90 secured againstthe side of the frame. The dampening roll is then moved upwardly to clear the sheetbed y114.

It will be apparent that the same operation takes place on rearward movement of the carriage, the dampening roller being tripped upwardly to clear the sheet bed and being moved downwardly to engage a plate on the plate bed, and then downwardly for engagement with the cylinder 21.

It should also be understood that a similar mechanism and cam arrangement is provided on the other side of the machine, for control of movement of the other end ofthe dampening roller 15.

It may be noted that the carriage is supported for movement along the frame by means of a plurality of rollers movableon the surface'69 and on a similar surface on the other side of the frame. As shown in Figure 4, one of such rollers, indicated by reference numeral 91, is journalled on a shaft 92 secured to the carriage.

In summary, the normal printing operation of the press is such that in the forward movement of the carriage, the dampening roller 15, the inking rollers 16-19 and the blanket cylinder 20 are sequentially brought into engagement with the plate on bed 13, the blanket cylinder being nonengaged with the sheet on bed 14. Thus substantially no time delay between the dampening of the plate and the inking of the plate or between the inking of the plate and the transfer of the image to the blanket cylinder. As is Vpointed out heretofore, this makes it possible to control the amount of moisture with much greater ease and precision and to obtain the proper amount of ink on the plate, with the ink being completely fresh when picked up by the blanket cylinder.

On reaching the forward end of the press, the carriage immediately starts back toward the rear end, the dampening roller 15 being engaged withthe plate on bed 13 to prevent complete drying thereof. When the carriage then reaches the rearward end of the press, water is applied to the dampening roller andink issimultaneously applied to the inking rollers. At this time, a sheet may be removed from the sheet bed 14, and replaced with a new sheet. Thus the complete cycle of operation consumes a minimum amount of time. Also, the fact that the water and ink-applying means are both located at one end of the machine, and are simultaneously operated, facilitates drive thereof from a common source.

It may also be noted that with the illustrated construction, the blanket cylinder is at the rearward end of the carriage and when the carriage is at the rearward end of the machine, the blanket cylinder is readily accessible for inspection.

It should be noted that it is necessary that a suicient number of inking rollers be used to obtain proper inking of the plate in a single pass in the normal printing operation. .Thus to obtainthe same efficiency in application of ink, the press requires twice as many rollers as used in prior` presses, in which the inking rollers engagethe plate on movement. of the carriage in bothdirectio-ns. Usually, four inkingrollers are required, as illustrated, compared with two rollers as customarily used in prior presses.

It will be understood that modicationsjand variations may be'eifected without departing from the spirit and scope of the novel concepts ofthis invention.

il claim as my invention:

l. kIn a printing .press including a plate bed anda sheet bed in spaced relation, a carriage .mounted for forward and rearward movement over Ysaid beds, a dampening roller journaled in said carriage andiarrangedgto engagea plate on said plate bed to apply moisture `Vthereto, inking rollers journaled in said carriage and Aarrangedtto `engage a plate on said plate bed to apply in'k thereto, a'blanket cylinder arranged to engage a plate on said plate ibed to receive an yimage .therefrom and to engage a sheet on said sheet bed to transfer the image thereto, means controlling said dampening and inking rollers to engage said dampening roller with the plate and immediately thereafter engage said inking rollers with the plate on forward movement of the carriage with said inking `rollersbeing tripped to elevated positions on rearward movement of said carriage, inking drum means journaled in the rearward end of said pass for applying ink to said inking rollers, a dampening cylinder journaled in the rearward end of said press for applying Water to said dampening roller, and means -for simultaneously operating said 'inking drum means and said dampening cylinder when said carriage is at said rearward end of said press.

2. In a printing press including a plate bed and a sheet bed in spaced relation, a carriage mounted for forward and rearward movement yover said beds, a dampening roller journaled in said carriage and arranged to engage a plate on saidplate bed to apply moisture-thereto, inking rollers journaled in said carriage and arranged to engage a plate on said plate bed to apply ink thereto, a blanket cylinder arranged to engage a plate on said plate bed to receive an image therefrom and 4to engage a sheet on said sheet bed to transfer the image thereto, means controlling said-dampening and inking rollers to engage said'dampening roller with the plate and immediately thereafter engage said inking rollers with the plate on forward rmovement ofthe carriage with said inking rollersibeing tripped to elevated positions on rearward movement of said carriage, inking drum means journaled in the rearward Vend of said press for applying ink to said inkingA rollers, a dampening cylinder journaled in the rearward end of said press for applying waterto said dampening roller, and means connecting said inking drum means and said dampening cylinder to a Acommon drive source for` simultaneously operating said inking drum means and said dampening cylinder when said carriage is at said rearward end of said press.

3. In a printing press including a'plate bed and-asheet bed in spaced relation, a carriage mountediforforward and rearward movement over said beds, a darnpening roller journaled in said carriage and arranged toengage a plate on said plate bed to apply moisture thereto, inking rollers journaled on said carriage and arranged to engage Vthe pla-te to apply ink thereto, a blanket cylinder arranged to engage the plate to receive an image therefromand to engage a sheet on said sheet bed to Vtransfer the image thereto, said inking rollers being journaled in said carriage between said dampening roller and said blanket cylinder, means `controlling said blanket cylinderand said inking and dampening rollers on forward movement of said carriage to engage said dampening roller with the plate, immediately thereafter engage said inking rollers with the plate and immediately thereafter engage said blanket cylinder with the plate, with the inking rollers being tripped to elevated positions on rearward movement of the said carriage, inking drum means journaled in the rearward end of said press for applying ink to said inking rollers, a dampening cylinder journaled in the rearward end of said press for applying water to said dampening roller, and means for simultaneously operating-said inking drum means and said dampening cylinder when said carriage is at said rearward end of said press.

4. In a printing pressincluding a plate bed and-asheet bed in spaced relation, a carriage mounted for forward -and rearward movement over said beds, a dampening roller vjournaledin said A.carriage and .arranged to engage a plate on said plate bed to apply moisture thereto, inking rollers journaled in said carriage and arranged to engage the plate to apply ink thereto, a blanket cylinder arranged to engage the plate to receive an image therefrom and to engage a sheet on said sheet bed to transfer the image thereto, means controlling said dampening and inking rollers to engage said dampening roller with the plate and immediately thereafter engage said inking rollers with the plate on forward movement of the carriage with said inking rollers being tripped to elevated positions on rearward movement of the carriage, means controlling said dampening roller to engage the plate during said rearward movement of said carriage, inking drum means journaled in the rearward end of said press for applying ink to said inking rollers, a dampening cylinder journaled in the rearward end of said press for applying water to said dampening roller, and means for simultaneously operating said inking drum means and said dampening cylinder when said carriage is at said rearward end of said press.

5. In a printing press including a plate bed and a sheet bed in spaced relation, a carriage mounted for movement from a rearward end of said press forwardly over said beds to a forward end of the press and thence from the forward end of the press rearwardly over said beds to said rearward end of said press, a dampening roller journaled in said carriage and arranged to engage a plate on said plate bed to apply moisture thereto, inking rollers journaled in said carriage and arranged to engage the plate to apply ink thereto, a blanket cylinder arranged to engage the plate to receive an image therefrom and to engage a sheet on said sheet bed to transfer the image thereto, inking drum means journaled in the rearward end portion of said press for applying ink to said inking rollers, a dampening cylinder journaled in said rearward end portion of said press 1for applying water to said dampening roller, and means for simultaneously operating said inking drum means and said dampening cylinder when said carriage is at said rearward end of said press, whereby said carriage after reaching said forward end of said press can remove immediately toward said rearward end of said press.

6. In a printing press including a plate bed and a sheet bed in spaced relation, a carriage mounted for reciprocatory movement over said beds, a dampening roller journaled in said carriage and arranged to engage a plate on said plate bed to apply moisture thereto, inking rollers journaled in said carriage and arranged to engage a plate on said plate bed to apply ink thereto, a blanket cylinder arranged to engage a plate on said plate bed to receive an image therefrom and to engage a sheet on said sheet bed to transfer the image thereto, said inking rollers being journaled in said carriage between said dampening roller and said blanket cylinder, and means controlling said blanket cylinder in said inking and dampening rollers on movement of said carriage in one direction to engage said dampening roller with the plate, immediately thereafter engage said inking rollers with the plate and immediately engage said blanket cylinder with the plate, with the inking rollers being tripped to elevated positions on movement of the carriage in the reverse direction, and with said dampening roller being engaged with the plate during said reverse movement of said carriage to prevent complete drying of the plate.

References Cited in the file of this patent UNITED STATES PATENTS 148,530 Waddie Mar. 10, 1874 505,961 Scott Oct. 3, 1893 634,616 I-Ialligan Oct. 10, 1899 984,9618 Read Feb. 2l, 1911 

